1. Field of the Invention
The present invention relates to a writing implement using, for example, oil based ink, such as a marker pen.
2. Description of the Prior Art
Conventionally, as a writing implement such as so-called marker pen, there is known a writing implement having a feeder core for feeding ink in an ink tank formed in a barrel cylinder to a pen tip and an ink collector formed by arranging a plurality of disk-shaped comb-tooth like elements at intervals in the axial direction of the feeder core.
Each of the comb-tooth like elements is constructed so that two center slits for feeding and storing ink in the ink tank into the ink collector are formed on both sides with centering around the feeder core, so that ink flowing out of the ink tank is temporarily stored in the ink collector via these center slits when the internal pressure of an ink tank space increases.
In the above-described conventional writing implement, if the residual amount of ink in the ink tank decreases to a certain value or smaller, when the writing implement is positioned in a horizontal posture, only one of the two center slits formed in the ink collector is tend to be immersed in ink.
In this state, air circulates between the ink tank and the ink collector via the other center slit that is not immersed in ink. As a result, the ink in the ink tank flows into the ink collector regardless of a change in pressure in the ink tank, which poses a problem in that the function inherent in the ink collector cannot be fulfilled.
Even in the ink collector formed with a single center slit, not limited to the above-described collector formed with two center slits, the above-described air circulation is produced in the state in which the whole of the center slit is not immersed in ink.
Also, when the pressure in the ink tank increases suddenly, the ink in the ink tank flows into not only the ink collector but also into the feeder core.
However, in the above-described conventional writing implement, although the center slits are formed in the comb-tooth like element, they are not formed so that the inner end thereof comes into contact with the feeder core, and therefore an excess of ink flowing into the feeder core cannot be absorbed by the ink collector.
Thus, the conventional writing implement has a problem in that the ink flowing out of the ink tank cannot be accumulated rapidly in the ink collector, and an excess of ink flowing into the feeder core leaks from the pen tip.
Accordingly, an object of the present invention is to provide a writing implement in which regardless of the residual amount of ink in an ink tank, even when the writing implement itself is positioned in a substantially horizontal posture, ink can be prevented from flowing into an ink collector, and also ink can be supplied smoothly.
Also, another object of the present invention is to provide a writing implement in which ink that is caused to flow out by a sudden change in pressure in the ink tank can be stored rapidly in the ink collector, and also ink can be prevented from leaking from a pen tip.
The present invention has been achieved to attain the above objects, and the aspects thereof will be as described below.
A first aspect of the present invention provides a writing implement having comprising: a feeder core for feeding ink in an ink tank to a pen tip; and an ink collector in which a plurality of comb-tooth like elements formed with an air-liquid exchange groove are arranged at intervals in the feeder core axial direction; wherein
an ink holding plate is provided so as to face the rear end face of the ink collector facing the ink tank in such a manner as to form a gap for holding the ink in the ink tank by means of the capillary phenomenon between the ink holding plate and the rear end face.
A second aspect of the present invention provides the writing implement in accordance with the above first aspect, wherein the ink holding plate is formed integrally with a holder for holding the feeder core.
A third aspect of the present invention provides the writing implement in accordance with the above second aspect, wherein the holder is formed with an ink supply section for supplying ink held between the ink holding plate and the ink collector into the feeder core.
A fourth aspect of the present invention provides a writing implement comprising; a feeder core for feeding ink in an ink tank to a pen tip; and an ink collector in which a plurality of comb-tooth like elements are arranged on the outer peripheral portion of the feeder core at intervals in the feeder core axial direction, wherein
a plurality of air exchange grooves for flowing and discharging ink of an amount responding to a change in pressure in the ink tank into and from grooves between the comb-tooth like elements are formed between an outer peripheral portion of the comb-tooth like element and an feeder core contact portion.
A fifth aspect of the present invention provides the writing implement in accordance with the above fourth aspect, wherein the air exchange grooves are formed in diametrical direction through the axis of the feeder core.
A sixth aspect of the present invention provides the writing implement in accordance with the fourth aspect, wherein an ink holding plate is provided so as to face the rear end face of the ink collector facing the ink tank in such a manner as to form a gap for holding the ink in the ink tank by means of the capillary phenomenon between the ink holding plate and the rear end face.
According to the above-described configuration, since ink can be held between the ink collector and the ink holding plate, the air-liquid exchange groove in the comb-tooth like element can be closed by being immersed in ink, so that the circulation of air via the air-liquid exchange groove can be inhibited. Therefore, ink does not flow into the ink collector, and also ink can be fed smoothly into the ink collector. Also, the ink holding plate can be formed easily, and thus the production cost can be reduced. Further, even when the ink in the ink tank does not come into contact with the feeder core, the ink can be supplied continuously into the feeder core.
Also, according to the present invention, when the pressure in the ink tank increases suddenly, the ink in the ink tank can be stored in the ink collector rapidly through the air exchange grooves in the ink collector, and an excess of ink flowing into the feeder core can also be stored in the ink collector rapidly via the feeder core contact portion of the air exchange groove. Also, the configuration is suitable for forming the ink collector. Further, since ink can be held between the rear end face of the ink collector and the ink holding plate, the air exchange grooves can be closed by being immersed in ink regardless of the residual amount of ink in the ink tank.